This invention relates to a feeding mechanism for metering a precise volume of particulate material.
Most particulate materials are comprised of both larger particles and more finely divided, powdery particles in an approximately randomly distributed mixture. Because of this random distribution, a mass of particulate material has a homogeneous aspect in that two randomly selected equal volumes of uncompacted material should include essentially the same mixture of coarser particles and more finely divided particles so that the same mass of material is present in the two volumes. When preselected masses of particulate material are volumetrically metered, it is imperative that the material be maintained in a state of uniform compactness so that successive volumetric units metered from a quantity of the material will contain the same mass. Moreover, the particulate material must be handled prior to volumetric metering in a manner so that the random distribution of coarser and nore finely divided material is not disturbed; that is, so that the powdery and granular constituents of the material are not stratified and separated out from one another.
Metering systems have been developed for feeding accurate quantities of particulate material. However, such systems are usually of complex and costly construction. Furthermore, a high degree of accuracy is obtainable only over a small range of masses. In contrast, the metering system of the present invention is of relatively simple and inexpensive construction and yet it is capable of dispensing particulate material, in an uncompacted and homogeneous condition, with a high degree of accuracy over a wide range of masses.